Synopsis: Searching for Dark Matter in Exoplanet Data

A satellite currently hunting for planets around distant stars could potentially spot black holes that some theories take for the missing dark matter.
Synopsis figure
NASA/Carter Roberts

Our galaxy could be filled with asteroid-size black holes that presumably formed shortly after the big bang. If they exist in large numbers, these so-called primordial black holes would serve as the dark matter that keeps stars gravitationally glued inside galaxies. None of these primordial black holes have been detected so far, but a new theoretical analysis described in Physical Review Letters demonstrates that a current planet-hunting mission is well placed to search for them.

As dark matter candidates go, primordial black holes are widely considered to be the dark horse. Previous astronomical searches for these objects came up empty, so many cosmologists put their money on the alternative candidate: a weakly interacting particle that physicists hope to find in accelerators or other experiments.

Still, there is a mass range of relatively small primordial black holes that has yet to be ruled out. Kim Griest, of the University of California in San Diego, and colleagues believe that part of this “observational gap” could be explored by piggybacking on a separate astronomy survey. NASA’s Kepler satellite was designed to search for planets around 150,000 stars (in a single field of view) that are relatively close to Earth. A planet passing in front of one of these stars dims the starlight by a small amount. Conversely, a black hole passing between us and a Kepler star would have the opposite effect: it would act as a lens and brighten the starlight. The authors calculate that Kepler is the first instrument sensitive enough to detect this so-called microlensing for black holes with masses of around 0.1% of an Earth mass. – Michael Schirber


More Features »


More Announcements »

Subject Areas

Particles and FieldsCosmology

Previous Synopsis

Nonlinear Dynamics

You Don’t Cite Me Anymore

Read More »

Next Synopsis

Related Articles

Viewpoint: Dark Matter Still at Large

Viewpoint: Dark Matter Still at Large

No dark matter particles have been observed by two of the world’s most sensitive direct-detection experiments, casting doubt on a favored dark matter model. Read More »

Viewpoint: Connecting the Bright and Dark Sides of Galaxies

Viewpoint: Connecting the Bright and Dark Sides of Galaxies

A universal law shows that the rotation of a disk galaxy is determined entirely by the visible matter it contains, even if the disk is mostly filled with dark matter. Read More »

Synopsis: Seeing Dark Matter Through the Clouds

Synopsis: Seeing Dark Matter Through the Clouds

A correlation between the cosmic microwave background and hydrogen absorption lines may reveal a connection between dark matter and intergalactic gas clouds. Read More »

More Articles